array push with OR operand

Question

There's a code written in javascript I have to re-use/modify and there's a line I don't understand:

var source, data = [];        
for (var id in this.target.target.layerSources) {
    source = this.target.target.layerSources[id];
    data.push([id, source.title || id, source.url]); //I don't understand this line
}

I looked it up but I don't find any example/explanation.

It's a null coalescing operator. [Here's an explanation](http://stackoverflow.com/questions/476436/is-there-a-null-coalescing-operator-in-javascript) — Patrick Read, Jun 13 '14 at 14:19

score 4 · Accepted Answer · edited Jun 13 '14 at 14:20

4

You are almost right, it means if source.title is falsy, it will take the variable id instead.

Falsy values are :

false
''
0
null
undefined
NaN

edited Jun 13 '14 at 14:20

axelduch

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answered Jun 13 '14 at 14:19

Karl-André Gagnon

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2

Ohhh alright. I assumed "id, source.title" and "id, source.url" were the two sides of the OR but it's just source.title and id. It makes so much more sense. Thanks mate. – Michael De Keyser Jun 13 '14 at 14:21

array push with OR operand

1 Answers1